电动剃须刀的齿轮组变形或缺润滑油卡可引起（）故障。
A.电动机不动作或刀片不动作
B.工作噪声大
C.剃须不锋利，有拔须感
D.充电指示灯不亮
参考答案：B
At the sight of the _____ scene, he was almost _____ to death.
A．frightened；frightening
B．frightened；frightened
C．frightening；frightening
D．frightening；frightened
煤尘分为有爆炸性煤尘和无爆炸性煤尘，有爆炸性煤尘才能爆炸。（）
